[MachineVerifier][GlobalISel] Verifying generic extends and truncates

[rtereshin]

Summary

Making sure we don't truncate / extend pointers, don't try to change
vector topology or bitcast vectors to scalars or back, and most
importantly, don't extend to a smaller type or truncate to a large
one.

While crafting a test for this change with a more or less decent code coverage I noticed that our MIR Parser is not able to parse vector pointer LLTs. We do quite explicitly support their representation in LLT class, and there is a direct counterpart in LLVM IR. Also it's easy to imagine a target actually sporting them (with some sort of vector scatter / gather stores / loads. So the test ended up depending on a fix for MIR Parser planned as a separate commit:

[MIRParser][GlobalISel] Parsing vector pointer types (<M x pA>)

MIParser wasn't able to parse LLTs like `<4 x p0>`, fixing that.

This diff includes both commits together.

[qcolombet]

test/CodeGen/AMDGPU/GlobalISel/regbankselect-trunc.mir

15 ↗

(On Diff #145353)

Haha, this is already paying back :)

[rtereshin]

Thank you, @qcolombet!

The parser part of this got a conflict with recently pushed https://reviews.llvm.org/D45948 (which got bug-fixed a bit in https://reviews.llvm.org/D46491), I'm going to resolve the conflict a tad later. I hope I can assume the revision is still accepted afterwards.

Best,
Roman

test/CodeGen/AMDGPU/GlobalISel/regbankselect-trunc.mir

15 ↗

(On Diff #145353)

;-)

[rtereshin]

I have updated the MIParser::parseLowLevelType part of the patch (as before, within a separate commit) resolving conflicts with Allow register class names in the form of integer/scalar and Improve error checking for typed immediate operands

llvm/trunk/lib/CodeGen/MIRParser/MIParser.cpp

bool MIParser::parseIRConstant(StringRef::iterator Loc, const Constant *&C) {
   lex();
   return false;
 }
 
 bool MIParser::parseLowLevelType(StringRef::iterator Loc, LLT &Ty) {
   if (Token.range().front() == 's' || Token.range().front() == 'p') {
     StringRef SizeStr = Token.range().drop_front();
     if (SizeStr.size() == 0 || !llvm::all_of(SizeStr, isdigit))
-      return error("Expected integers after 's'/'p' type character");
+      return error("expected integers after 's'/'p' type character");
   }
 
   if (Token.range().front() == 's') {
     Ty = LLT::scalar(APSInt(Token.range().drop_front()).getZExtValue());
     lex();
     return false;
   } else if (Token.range().front() == 'p') {
     const DataLayout &DL = MF.getDataLayout();
     unsigned AS = APSInt(Token.range().drop_front()).getZExtValue();
     Ty = LLT::pointer(AS, DL.getPointerSizeInBits(AS));
     lex();
     return false;
   }
 
   // Now we're looking for a vector.
   if (Token.isNot(MIToken::less))
     return error(Loc,
-                 "expected unsized, pN, sN or <N x sM> for GlobalISel type");
-
+                 "expected sN, pA, <M x sN>, or <M x pA> for GlobalISel type");
   lex();
 
   if (Token.isNot(MIToken::IntegerLiteral))
-    return error(Loc, "expected <N x sM> for vctor type");
+    return error(Loc, "expected <M x sN> or <M x pA> for vector type");
   uint64_t NumElements = Token.integerValue().getZExtValue();
   lex();
 
   if (Token.isNot(MIToken::Identifier) || Token.stringValue() != "x")
-    return error(Loc, "expected '<N x sM>' for vector type");
+    return error(Loc, "expected <M x sN> or <M x pA> for vector type");
   lex();
 
-  if (Token.range().front() != 's')
-    return error(Loc, "expected '<N x sM>' for vector type");
+  if (Token.range().front() != 's' && Token.range().front() != 'p')
+    return error(Loc, "expected <M x sN> or <M x pA> for vector type");
   StringRef SizeStr = Token.range().drop_front();
   if (SizeStr.size() == 0 || !llvm::all_of(SizeStr, isdigit))
-    return error("Expected integers after 's' type character");
-  uint64_t ScalarSize = APSInt(Token.range().drop_front()).getZExtValue();
+    return error("expected integers after 's'/'p' type character");
+
+  if (Token.range().front() == 's')
+    Ty = LLT::scalar(APSInt(Token.range().drop_front()).getZExtValue());
+  else if (Token.range().front() == 'p') {
+    const DataLayout &DL = MF.getDataLayout();
+    unsigned AS = APSInt(Token.range().drop_front()).getZExtValue();
+    Ty = LLT::pointer(AS, DL.getPointerSizeInBits(AS));
+  } else
+    return error(Loc, "expected <M x sN> or <M x pA> for vector type");
   lex();
 
   if (Token.isNot(MIToken::greater))
-    return error(Loc, "expected '<N x sM>' for vector type");
+    return error(Loc, "expected <M x sN> or <M x pA> for vector type");
   lex();
 
-  Ty = LLT::vector(NumElements, ScalarSize);
+  Ty = LLT::vector(NumElements, Ty);
   return false;
 }
 
 bool MIParser::parseTypedImmediateOperand(MachineOperand &Dest) {
   assert(Token.is(MIToken::Identifier));
   StringRef TypeStr = Token.range();
   if (TypeStr.front() != 'i' && TypeStr.front() != 's' &&
       TypeStr.front() != 'p')
     return error(
-        "A typed immediate operand should start with one of 'i', 's', or 'p'");
+        "a typed immediate operand should start with one of 'i', 's', or 'p'");
   StringRef SizeStr = Token.range().drop_front();
   if (SizeStr.size() == 0 || !llvm::all_of(SizeStr, isdigit))
-    return error("Expected integers after 'i'/'s'/'p' type character");
+    return error("expected integers after 'i'/'s'/'p' type character");
 
   auto Loc = Token.location();
   lex();
   if (Token.isNot(MIToken::IntegerLiteral))
     return error("expected an integer literal");
   const Constant *C = nullptr;
   if (parseIRConstant(Loc, C))
     return true;

llvm/trunk/test/CodeGen/MIR/AArch64/parse-low-level-type-invalid0.mir

+# RUN: not llc -mtriple=aarch64-- -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
+# When a low-level type is only a single 's'/'p' character
+---
+name: test_low_level_type_is_single_s_p
+body: |
+  bb.0:
+    liveins: $x0
+    ; CHECK: [[@LINE+1]]:10: expected integers after 's'/'p' type character
+    %0:_(s) = COPY $x0
+...

llvm/trunk/test/CodeGen/MIR/AArch64/parse-low-level-type-invalid1.mir

+# RUN: not llc -mtriple=aarch64-- -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
+# When a low-level type does not start with 's', 'p', or '<'
+---
+name: test_low_level_type_does_not_start_with_s_p_lt
+body: |
+  bb.0:
+    liveins: $x0
+    ; CHECK: [[@LINE+1]]:10: expected sN, pA, <M x sN>, or <M x pA> for GlobalISel type
+    %0:_(i64) = COPY $x0
+...

llvm/trunk/test/CodeGen/MIR/AArch64/parse-low-level-type-invalid2.mir

+# RUN: not llc -mtriple=aarch64-- -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
+# When a low-level type is a vector with only a single 's'/'p' character for element type
+---
+name: test_low_level_type_is_single_s_p
+body: |
+  bb.0:
+    liveins: $q0
+    ; CHECK: [[@LINE+1]]:15: expected integers after 's'/'p' type character
+    %0:_(<2 x p>) = COPY $q0
+...

llvm/trunk/test/CodeGen/MIR/AArch64/parse-low-level-type-invalid3.mir

+# RUN: not llc -mtriple=aarch64-- -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
+# When a low-level type is a vector which element type does not start with 's' or 'p'
+---
+name: test_low_level_type_does_not_start_with_s_p
+body: |
+  bb.0:
+    liveins: $q0
+    ; CHECK: [[@LINE+1]]:10: expected <M x sN> or <M x pA> for vector type
+    %0:_(<2 x i64>) = COPY $q0
+...

llvm/trunk/test/CodeGen/MIR/AArch64/print-parse-vector-of-pointers-llt.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=aarch64-- -run-pass none -o - %s 2>&1 | FileCheck %s
+---
+name: test_vector_of_pointers_llt
+body: |
+  bb.0:
+    liveins: $q0
+    ; CHECK-LABEL: name: test_vector_of_pointers_llt
+    ; CHECK: [[COPY:%[0-9]+]]:_(<2 x p0>) = COPY $q0
+    %0:_(<2 x p0>) = COPY $q0
+...

llvm/trunk/test/CodeGen/MIR/WebAssembly/typed-immediate-operand-invalid0.mir

 # RUN: not llc -mtriple=wasm32-unknown-unknown -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
 # When a typed immediate operand is only a single 'i'/'s'/'p' character
 ---
 name: test_typed_immediate_operand_invalid0
 liveins:
   - { reg: '$arguments' }
 body: |
   bb.0:
     liveins: $arguments
-    ; CHECK: [[@LINE+1]]:24: Expected integers after 'i'/'s'/'p' type character
+    ; CHECK: [[@LINE+1]]:24: expected integers after 'i'/'s'/'p' type character
     %0:i32 = CONST_I32 i 0, implicit-def dead $arguments
     RETURN_VOID implicit-def dead $arguments
 ...

llvm/trunk/test/CodeGen/MIR/WebAssembly/typed-immediate-operand-invalid1.mir

 # RUN: not llc -mtriple=wasm32-unknown-unknown -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
 # When a typed immediate operand does not start with 'i', 's', or 'p'
 ---
 name: test_typed_immediate_operand_invalid1
 liveins:
   - { reg: '$arguments' }
 body: |
   bb.0:
     liveins: $arguments
-    ; CHECK: [[@LINE+1]]:24: A typed immediate operand should start with one of 'i', 's', or 'p'
+    ; CHECK: [[@LINE+1]]:24: a typed immediate operand should start with one of 'i', 's', or 'p'
     %0:i32 = CONST_I32 abc 0, implicit-def dead $arguments
     RETURN_VOID implicit-def dead $arguments
 ...